The present invention relates to the field of user interfaces for portable and handheld electronic devices. Many portable and handheld electronic devices include components such as display devices, audio input and output devices, cameras, volatile and non-volatile storage, microprocessors, and/or wired, wireless, or cellular network interfaces. As such, many of these devices may be potentially capable of a wide variety of functions, including displaying images and video; playing games; playing music; recording images or video; sending and receiving text messages, e-mail, and instant messages; initiating and receiving telephone calls; videoconferencing; and browsing web sites; and running business or other types of application software.
Despite the capabilities of the components of handheld and portable electronic devices, may users prefer devices that perform only one or two primary functions. For example, users may have a handheld music player to listen to digital audio files, a cellular telephone to make telephone calls; and a wireless e-mail device for exchanging e-mails. One reason for this is that most handheld and portable electronic devices do not provide a simple and intuitive user interface for multiple disparate functions. For example, many users prefer a thumb-size QWERTY keyboard for exchanging e-mails, a touch sensitive scroll-wheel, touchpad, or slide to access digital music and videos, and a directional-pad or joystick for playing games. Because of the small size of handheld and portable electronic devices, it is difficult to include all of these different types of interfaces on the surface of the device. Moreover, even if these different interfaces are included, the result is often a cluttered, confusing interface of limited utility.
One prior approach uses a touch screen for a user interface. The touch screen can be configured to display images of one or more virtual user interfaces and can detect user interactions with each virtual interface. Although the touch screen allows for a wide variety of different virtual interfaces, the quality of the user experience is often poor. Touch screens do not provide any tactile feedback to users. This substantially degrades the quality of the user experience because users cannot distinguish virtual user interface elements by touch and must look at the touch screen to interact with the virtual interface. Moreover, the responsiveness of touch screens is slow and fingerprints tend to mar the appearance of the touch screen.
It is therefore desirable for a device to include multiple separate physical interfaces dedicated to different tasks. It is also desirable for the device to integrate multiple separate physical interfaces in a small form factor. It is further desirable for the device to enable users to access different interfaces in an intuitive manner.
In the drawings, the use of identical reference numbers indicates identical components.